CM4 socket:suitable for all variants of Compute Module 4 Micro-SD card slot:for connecting a Micro-SD card with pre-burnt image (Lite variant ONLY) 40PIN GPIO header:for connecting sorts of HATs Gigabit Ethernet RJ45 connector:Power supply / Programming,5V power supply, or used for eMMC burning,3.5mm audio jack User button:USB2.0 connector,for connecting sorts of USB devices CSI connector:MIPI CSI camera interface DSI connector:MIPI DSI display interface MP1658:Mini HDMI connector,supports 4K 30fps output BOOT switch: ON: Switch USB to Type C interface, will enter download mode when powered on (configured as a large-capacity disk through RPI boot) OFF: Switch USB to Type A interface, will not enter download mode when powered on (booted from eMMC or Micro-SD card) Colour:As Shown Material:PC Due to different batches, there may be differences in product appearance and printed text, which will not affect use Package Contents: 3 x CM4-NANO-B(GPIO NOT Soldered) 3pcs 2 x 20PIN header